This application in general relates to an improved system for monitoring a plurality of sample vials, and making a determination of whether the sample vials are experiencing bacterial growth.
Sample vials are prepared by injecting a body fluid sample into a culture medium in a sample vial. The sample vial is then incubated, and tested for bacterial growth. Systems for detecting bacterial growth in sample vials are known, wherein a large number of sample vials are repeatedly and periodically tested for the presence of bacterial growth. Several types of sensors are known which have changing responses to a light input based on conditions within the sample vial. By monitoring the sensor response one can determine whether there is bacterial growth.
Generally, in known sensors light is directed into the sample vial or sensor. Light reemerging from the sample vial, or from the sensor, is monitored to determine whether bacterial growth is occurring in the sample vial. Such sensors and associated methods of determination are known in the art, and the types of changes which indicate bacterial growth are known.
Known test systems typically hold a large number of such sample vials. In one example, they hold 240 sample vials. With the known systems an individual light source, an individual photodetector and the required wiring are associated with each sample vial. Thus, such systems are complicated and expensive. Due to the large number of light sources and detectors which are required, such systems have sometimes utilized less expensive light sources or detectors than those which may be most desirable. Also, since several hundred light sources and photodetectors are utilized within each system, station to station variations are inevitable. That is, a light source associated with a first station may emit light at a different intensity than the other stations. Variation could also occur between the photodetectors associated with the hundreds of stations. This could result in potential variations in readings between vials within the system. Such variations are undesirable.
Another problem with the prior art systems is that the only identification of a vial located at a particular station within the system is by a manual bar code reading before the vial is placed into the station. Thus, if an operator misplaces the vial within the station, there may be misidentification of the location of the vial within the station.
Finally, as discussed above, there are several types of sensors which may be utilized to determine the presence of bacterial growth. Each type of sensor has beneficial characteristics, and other characteristics that are undesirable. Further, certain types of bacteria are better detected by certain types of sensors. Thus, no one single type of sensor provides all desirable characteristics. Even so, the prior art has typically utilized vials with only a single type sensor incorporated into the vial.